matplotlib/lib/matplotlib/animation.py at patch-1 · flothesof/matplotlib · GitHub

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# TODO:

# * Loop Delay is broken on GTKAgg. This is because source_remove() is not

# working as we want. PyGTK bug?

# * Documentation -- this will need a new section of the User's Guide.

# Both for Animations and just timers.

# - Also need to update http://www.scipy.org/Cookbook/Matplotlib/Animations

# * Blit

# * Currently broken with Qt4 for widgets that don't start on screen

# * Still a few edge cases that aren't working correctly

# * Can this integrate better with existing matplotlib animation artist flag?

# - If animated removes from default draw(), perhaps we could use this to

# simplify initial draw.

# * Example

# * Frameless animation - pure procedural with no loop

# * Need example that uses something like inotify or subprocess

# * Complex syncing examples

# * Movies

# * Can blit be enabled for movies?

# * Need to consider event sources to allow clicking through multiple figures

from __future__ import (absolute_import, division, print_function,

unicode_literals)

from matplotlib.externals import six

from matplotlib.externals.six.moves import xrange, zip

import os

import platform

import sys

import itertools

import base64

import contextlib

import tempfile

from matplotlib.cbook import iterable, is_string_like

from matplotlib.compat import subprocess

from matplotlib import verbose

from matplotlib import rcParams

# Process creation flag for subprocess to prevent it raising a terminal

# window. See for example:

# https://stackoverflow.com/questions/24130623/using-python-subprocess-popen-cant-prevent-exe-stopped-working-prompt

if platform.system() == 'Windows':

CREATE_NO_WINDOW = 0x08000000

subprocess_creation_flags = CREATE_NO_WINDOW

else:

# Apparently None won't work here

subprocess_creation_flags = 0

# Other potential writing methods:

# * http://pymedia.org/

# * libmng (produces swf) python wrappers: https://github.com/libming/libming

# * Wrap x264 API:

# (http://stackoverflow.com/questions/2940671/

# how-to-encode-series-of-images-into-h264-using-x264-api-c-c )

# A registry for available MovieWriter classes

class MovieWriterRegistry(object):

def __init__(self):

self.avail = dict()

# Returns a decorator that can be used on classes to register them under

# a name. As in:

# @register('foo')

# class Foo:

# pass

def register(self, name):

def wrapper(writerClass):

if writerClass.isAvailable():

self.avail[name] = writerClass

return writerClass

return wrapper

def list(self):

''' Get a list of available MovieWriters.'''

return list(self.avail.keys())

def is_available(self, name):

return name in self.avail

def __getitem__(self, name):

if not self.avail:

raise RuntimeError("No MovieWriters available!")

return self.avail[name]

writers = MovieWriterRegistry()

class MovieWriter(object):

'''

Base class for writing movies. Fundamentally, what a MovieWriter does

is provide is a way to grab frames by calling grab_frame(). setup()

is called to start the process and finish() is called afterwards.

This class is set up to provide for writing movie frame data to a pipe.

saving() is provided as a context manager to facilitate this process as::

with moviewriter.saving('myfile.mp4'):

# Iterate over frames

moviewriter.grab_frame()

The use of the context manager ensures that setup and cleanup are

performed as necessary.

frame_format: string

The format used in writing frame data, defaults to 'rgba'

'''

def __init__(self, fps=5, codec=None, bitrate=None, extra_args=None,

metadata=None):

'''

Construct a new MovieWriter object.

fps: int

Framerate for movie.

codec: string or None, optional

The codec to use. If None (the default) the setting in the

rcParam `animation.codec` is used.

bitrate: int or None, optional

The bitrate for the saved movie file, which is one way to control

the output file size and quality. The default value is None,

which uses the value stored in the rcParam `animation.bitrate`.

A value of -1 implies that the bitrate should be determined

automatically by the underlying utility.

extra_args: list of strings or None

A list of extra string arguments to be passed to the underlying

movie utiltiy. The default is None, which passes the additional

argurments in the 'animation.extra_args' rcParam.

metadata: dict of string:string or None

A dictionary of keys and values for metadata to include in the

output file. Some keys that may be of use include:

title, artist, genre, subject, copyright, srcform, comment.

'''

self.fps = fps

self.frame_format = 'rgba'

if codec is None:

self.codec = rcParams['animation.codec']

else:

self.codec = codec

if bitrate is None:

self.bitrate = rcParams['animation.bitrate']

else:

self.bitrate = bitrate

if extra_args is None:

self.extra_args = list(rcParams[self.args_key])

else:

self.extra_args = extra_args

if metadata is None:

self.metadata = dict()

else:

self.metadata = metadata

@property

def frame_size(self):

'A tuple (width,height) in pixels of a movie frame.'

width_inches, height_inches = self.fig.get_size_inches()

return width_inches * self.dpi, height_inches * self.dpi

def setup(self, fig, outfile, dpi, *args):

'''

Perform setup for writing the movie file.

fig: `matplotlib.Figure` instance

The figure object that contains the information for frames

outfile: string

The filename of the resulting movie file

dpi: int

The DPI (or resolution) for the file. This controls the size

in pixels of the resulting movie file.

'''

self.outfile = outfile

self.fig = fig

self.dpi = dpi

# Run here so that grab_frame() can write the data to a pipe. This

# eliminates the need for temp files.

self._run()

@contextlib.contextmanager

def saving(self, *args):

'''

Context manager to facilitate writing the movie file.

``*args`` are any parameters that should be passed to `setup`.

'''

# This particular sequence is what contextlib.contextmanager wants

self.setup(*args)

yield

self.finish()

def _run(self):

# Uses subprocess to call the program for assembling frames into a

# movie file. *args* returns the sequence of command line arguments

# from a few configuration options.

command = self._args()

if verbose.ge('debug'):

output = sys.stdout

else:

output = subprocess.PIPE

verbose.report('MovieWriter.run: running command: %s' %

' '.join(command))

self._proc = subprocess.Popen(command, shell=False,

stdout=output, stderr=output,

stdin=subprocess.PIPE,

creationflags=subprocess_creation_flags)

def finish(self):

'Finish any processing for writing the movie.'

self.cleanup()

def grab_frame(self, **savefig_kwargs):

'''

Grab the image information from the figure and save as a movie frame.

All keyword arguments in savefig_kwargs are passed on to the 'savefig'

command that saves the figure.

'''

verbose.report('MovieWriter.grab_frame: Grabbing frame.',

level='debug')

try:

# Tell the figure to save its data to the sink, using the

# frame format and dpi.

self.fig.savefig(self._frame_sink(), format=self.frame_format,

dpi=self.dpi, **savefig_kwargs)

except RuntimeError:

out, err = self._proc.communicate()

verbose.report('MovieWriter -- Error '

'running proc:\n%s\n%s' % (out,

err), level='helpful')

raise

def _frame_sink(self):

'Returns the place to which frames should be written.'

return self._proc.stdin

def _args(self):

'Assemble list of utility-specific command-line arguments.'

return NotImplementedError("args needs to be implemented by subclass.")

def cleanup(self):

'Clean-up and collect the process used to write the movie file.'

out, err = self._proc.communicate()

self._frame_sink().close()

verbose.report('MovieWriter -- '

'Command stdout:\n%s' % out, level='debug')

verbose.report('MovieWriter -- '

'Command stderr:\n%s' % err, level='debug')

@classmethod

def bin_path(cls):

'''

Returns the binary path to the commandline tool used by a specific

subclass. This is a class method so that the tool can be looked for

before making a particular MovieWriter subclass available.

'''

return rcParams[cls.exec_key]

@classmethod

def isAvailable(cls):

'''

Check to see if a MovieWriter subclass is actually available by

running the commandline tool.

'''

try:

p = subprocess.Popen(cls.bin_path(),

shell=False,

stdout=subprocess.PIPE,

stderr=subprocess.PIPE,

creationflags=subprocess_creation_flags)

p.communicate()

return True

except OSError:

return False

class FileMovieWriter(MovieWriter):

'`MovieWriter` subclass that handles writing to a file.'

def __init__(self, *args, **kwargs):

MovieWriter.__init__(self, *args, **kwargs)

self.frame_format = rcParams['animation.frame_format']

def setup(self, fig, outfile, dpi, frame_prefix='_tmp', clear_temp=True):

'''

Perform setup for writing the movie file.

fig: `matplotlib.Figure` instance

The figure object that contains the information for frames

outfile: string

The filename of the resulting movie file

dpi: int

The DPI (or resolution) for the file. This controls the size

in pixels of the resulting movie file.

frame_prefix: string, optional

The filename prefix to use for the temporary files. Defaults

to '_tmp'

clear_temp: bool

Specifies whether the temporary files should be deleted after

the movie is written. (Useful for debugging.) Defaults to True.

'''

self.fig = fig

self.outfile = outfile

self.dpi = dpi

self.clear_temp = clear_temp

self.temp_prefix = frame_prefix

self._frame_counter = 0 # used for generating sequential file names

self._temp_names = list()

self.fname_format_str = '%s%%07d.%s'

@property

def frame_format(self):

'''

Format (png, jpeg, etc.) to use for saving the frames, which can be

decided by the individual subclasses.

'''

return self._frame_format

@frame_format.setter

def frame_format(self, frame_format):

if frame_format in self.supported_formats:

self._frame_format = frame_format

else:

self._frame_format = self.supported_formats[0]

def _base_temp_name(self):

# Generates a template name (without number) given the frame format

# for extension and the prefix.

return self.fname_format_str % (self.temp_prefix, self.frame_format)

def _frame_sink(self):

# Creates a filename for saving using the basename and the current

# counter.

fname = self._base_temp_name() % self._frame_counter

# Save the filename so we can delete it later if necessary

self._temp_names.append(fname)

verbose.report(

'FileMovieWriter.frame_sink: saving frame %d to fname=%s' %

(self._frame_counter, fname),

level='debug')

self._frame_counter += 1 # Ensures each created name is 'unique'

# This file returned here will be closed once it's used by savefig()

# because it will no longer be referenced and will be gc-ed.

return open(fname, 'wb')

def grab_frame(self, **savefig_kwargs):

'''

Grab the image information from the figure and save as a movie frame.

All keyword arguments in savefig_kwargs are passed on to the 'savefig'

command that saves the figure.

'''

# Overloaded to explicitly close temp file.

verbose.report('MovieWriter.grab_frame: Grabbing frame.',

level='debug')

try:

# Tell the figure to save its data to the sink, using the

# frame format and dpi.

myframesink = self._frame_sink()

self.fig.savefig(myframesink, format=self.frame_format,

dpi=self.dpi, **savefig_kwargs)

myframesink.close()

except RuntimeError:

out, err = self._proc.communicate()

verbose.report('MovieWriter -- Error '

'running proc:\n%s\n%s' % (out,

err), level='helpful')

raise

def finish(self):

# Call run here now that all frame grabbing is done. All temp files

# are available to be assembled.

self._run()

MovieWriter.finish(self) # Will call clean-up

# Check error code for creating file here, since we just run

# the process here, rather than having an open pipe.

if self._proc.returncode:

raise RuntimeError('Error creating movie, return code: '

+ str(self._proc.returncode)

+ ' Try running with --verbose-debug')

def cleanup(self):

MovieWriter.cleanup(self)

# Delete temporary files

if self.clear_temp:

verbose.report(

'MovieWriter: clearing temporary fnames=%s' %

str(self._temp_names),

level='debug')

for fname in self._temp_names:

os.remove(fname)

# Base class of ffmpeg information. Has the config keys and the common set

# of arguments that controls the *output* side of things.

class FFMpegBase(object):

exec_key = 'animation.ffmpeg_path'

args_key = 'animation.ffmpeg_args'

@property

def output_args(self):

# The %dk adds 'k' as a suffix so that ffmpeg treats our bitrate as in

# kbps

args = ['-vcodec', self.codec]

# For h264, the default format is yuv444p, which is not compatible

# with quicktime (and others). Specifying yuv420p fixes playback on

# iOS,as well as HTML5 video in firefox and safari (on both Win and

# OSX). Also fixes internet explorer. This is as of 2015/10/29.

if self.codec == 'h264' and '-pix_fmt' not in self.extra_args:

args.extend(['-pix_fmt', 'yuv420p'])

if self.bitrate > 0:

args.extend(['-b', '%dk' % self.bitrate])

if self.extra_args:

args.extend(self.extra_args)

for k, v in six.iteritems(self.metadata):

args.extend(['-metadata', '%s=%s' % (k, v)])

return args + ['-y', self.outfile]

# Combine FFMpeg options with pipe-based writing

@writers.register('ffmpeg')

class FFMpegWriter(MovieWriter, FFMpegBase):

def _args(self):

# Returns the command line parameters for subprocess to use

# ffmpeg to create a movie using a pipe.

args = [self.bin_path(), '-f', 'rawvideo', '-vcodec', 'rawvideo',

'-s', '%dx%d' % self.frame_size, '-pix_fmt', self.frame_format,

'-r', str(self.fps)]

# Logging is quieted because subprocess.PIPE has limited buffer size.

if not verbose.ge('debug'):

args += ['-loglevel', 'quiet']

args += ['-i', 'pipe:'] + self.output_args

return args

# Combine FFMpeg options with temp file-based writing

@writers.register('ffmpeg_file')

class FFMpegFileWriter(FileMovieWriter, FFMpegBase):

supported_formats = ['png', 'jpeg', 'ppm', 'tiff', 'sgi', 'bmp',

'pbm', 'raw', 'rgba']

def _args(self):

# Returns the command line parameters for subprocess to use

# ffmpeg to create a movie using a collection of temp images

return [self.bin_path(), '-r', str(self.fps),

'-i', self._base_temp_name(),

'-vframes', str(self._frame_counter),

'-r', str(self.fps)] + self.output_args

# Base class of avconv information. AVConv has identical arguments to

# FFMpeg

class AVConvBase(FFMpegBase):

exec_key = 'animation.avconv_path'

args_key = 'animation.avconv_args'

# Combine AVConv options with pipe-based writing

@writers.register('avconv')

class AVConvWriter(AVConvBase, FFMpegWriter):

pass

# Combine AVConv options with file-based writing

@writers.register('avconv_file')

class AVConvFileWriter(AVConvBase, FFMpegFileWriter):

pass

# Base class of mencoder information. Contains configuration key information

# as well as arguments for controlling *output*

class MencoderBase(object):

exec_key = 'animation.mencoder_path'

args_key = 'animation.mencoder_args'

# Mencoder only allows certain keys, other ones cause the program

# to fail.

allowed_metadata = ['name', 'artist', 'genre', 'subject', 'copyright',

'srcform', 'comment']

# Mencoder mandates using name, but 'title' works better with ffmpeg.

# If we find it, just put it's value into name

def _remap_metadata(self):

if 'title' in self.metadata:

self.metadata['name'] = self.metadata['title']

@property

def output_args(self):

self._remap_metadata()

lavcopts = {'vcodec': self.codec}

if self.bitrate > 0:

lavcopts.update(vbitrate=self.bitrate)

args = ['-o', self.outfile, '-ovc', 'lavc', '-lavcopts',

':'.join(itertools.starmap('{0}={1}'.format,

lavcopts.items()))]

if self.extra_args:

args.extend(self.extra_args)

if self.metadata:

args.extend(['-info', ':'.join('%s=%s' % (k, v)

for k, v in six.iteritems(self.metadata)

if k in self.allowed_metadata)])

return args

# Combine Mencoder options with pipe-based writing

@writers.register('mencoder')

class MencoderWriter(MovieWriter, MencoderBase):

def _args(self):

# Returns the command line parameters for subprocess to use

# mencoder to create a movie

return [self.bin_path(), '-', '-demuxer', 'rawvideo', '-rawvideo',

('w=%i:h=%i:' % self.frame_size +

'fps=%i:format=%s' % (self.fps,

self.frame_format))] + self.output_args

# Combine Mencoder options with temp file-based writing

@writers.register('mencoder_file')

class MencoderFileWriter(FileMovieWriter, MencoderBase):

supported_formats = ['png', 'jpeg', 'tga', 'sgi']

def _args(self):

# Returns the command line parameters for subprocess to use

# mencoder to create a movie

return [self.bin_path(),

'mf://%s*.%s' % (self.temp_prefix, self.frame_format),

'-frames', str(self._frame_counter), '-mf',

'type=%s:fps=%d' % (self.frame_format,

self.fps)] + self.output_args

# Base class for animated GIFs with convert utility

class ImageMagickBase(object):

exec_key = 'animation.convert_path'

args_key = 'animation.convert_args'

@property

def delay(self):

return 100. / self.fps

@property

def output_args(self):

return [self.outfile]

@writers.register('imagemagick')

class ImageMagickWriter(MovieWriter, ImageMagickBase):

def _args(self):

return ([self.bin_path(),

'-size', '%ix%i' % self.frame_size, '-depth', '8',

'-delay', str(self.delay), '-loop', '0',

'%s:-' % self.frame_format]

+ self.output_args)

@writers.register('imagemagick_file')

class ImageMagickFileWriter(FileMovieWriter, ImageMagickBase):

supported_formats = ['png', 'jpeg', 'ppm', 'tiff', 'sgi', 'bmp',

'pbm', 'raw', 'rgba']

def _args(self):

return ([self.bin_path(), '-delay', str(self.delay), '-loop', '0',

'%s*.%s' % (self.temp_prefix, self.frame_format)]

+ self.output_args)

class Animation(object):

'''

This class wraps the creation of an animation using matplotlib. It is

only a base class which should be subclassed to provide needed behavior.

*fig* is the figure object that is used to get draw, resize, and any

other needed events.

*event_source* is a class that can run a callback when desired events

are generated, as well as be stopped and started. Examples include timers

(see :class:`TimedAnimation`) and file system notifications.

*blit* is a boolean that controls whether blitting is used to optimize

drawing.

'''

def __init__(self, fig, event_source=None, blit=False):

self._fig = fig

# Disables blitting for backends that don't support it. This

# allows users to request it if available, but still have a

# fallback that works if it is not.

self._blit = blit and fig.canvas.supports_blit

# These are the basics of the animation. The frame sequence represents

# information for each frame of the animation and depends on how the

# drawing is handled by the subclasses. The event source fires events

# that cause the frame sequence to be iterated.

self.frame_seq = self.new_frame_seq()

self.event_source = event_source

# Instead of starting the event source now, we connect to the figure's

# draw_event, so that we only start once the figure has been drawn.

self._first_draw_id = fig.canvas.mpl_connect('draw_event', self._start)

# Connect to the figure's close_event so that we don't continue to

# fire events and try to draw to a deleted figure.

self._close_id = self._fig.canvas.mpl_connect('close_event',

self._stop)

if self._blit:

self._setup_blit()

def _start(self, *args):

'''

Starts interactive animation. Adds the draw frame command to the GUI

handler, calls show to start the event loop.

'''

# First disconnect our draw event handler

self._fig.canvas.mpl_disconnect(self._first_draw_id)

self._first_draw_id = None # So we can check on save

# Now do any initial draw

self._init_draw()

# Add our callback for stepping the animation and

# actually start the event_source.

self.event_source.add_callback(self._step)

self.event_source.start()

def _stop(self, *args):

# On stop we disconnect all of our events.

if self._blit:

self._fig.canvas.mpl_disconnect(self._resize_id)

self._fig.canvas.mpl_disconnect(self._close_id)

self.event_source.remove_callback(self._step)

self.event_source = None

def save(self, filename, writer=None, fps=None, dpi=None, codec=None,

bitrate=None, extra_args=None, metadata=None, extra_anim=None,

savefig_kwargs=None):

'''

Saves a movie file by drawing every frame.

*filename* is the output filename, e.g., :file:`mymovie.mp4`

*writer* is either an instance of :class:`MovieWriter` or a string

key that identifies a class to use, such as 'ffmpeg' or 'mencoder'.

If nothing is passed, the value of the rcparam `animation.writer` is

used.

*fps* is the frames per second in the movie. Defaults to None,

which will use the animation's specified interval to set the frames

per second.

*dpi* controls the dots per inch for the movie frames. This combined

with the figure's size in inches controls the size of the movie.

*codec* is the video codec to be used. Not all codecs are supported

by a given :class:`MovieWriter`. If none is given, this defaults to the

value specified by the rcparam `animation.codec`.

*bitrate* specifies the amount of bits used per second in the

compressed movie, in kilobits per second. A higher number means a

higher quality movie, but at the cost of increased file size. If no

value is given, this defaults to the value given by the rcparam

`animation.bitrate`.

*extra_args* is a list of extra string arguments to be passed to the

underlying movie utiltiy. The default is None, which passes the

additional argurments in the 'animation.extra_args' rcParam.

*metadata* is a dictionary of keys and values for metadata to include

in the output file. Some keys that may be of use include:

title, artist, genre, subject, copyright, srcform, comment.

*extra_anim* is a list of additional `Animation` objects that should

be included in the saved movie file. These need to be from the same

`matplotlib.Figure` instance. Also, animation frames will just be

simply combined, so there should be a 1:1 correspondence between

the frames from the different animations.

*savefig_kwargs* is a dictionary containing keyword arguments to be

passed on to the 'savefig' command which is called repeatedly to save

the individual frames. This can be used to set tight bounding boxes,

for example.

'''

if savefig_kwargs is None:

savefig_kwargs = {}

# FIXME: Using 'bbox_inches' doesn't currently work with

# writers that pipe the data to the command because this

# requires a fixed frame size (see Ryan May's reply in this

# thread: [1]). Thus we drop the 'bbox_inches' argument if it

# exists in savefig_kwargs.

# [1] (http://matplotlib.1069221.n5.nabble.com/

# Animation-class-let-save-accept-kwargs-which-

# are-passed-on-to-savefig-td39627.html)

if 'bbox_inches' in savefig_kwargs:

if not (writer in ['ffmpeg_file', 'mencoder_file'] or

isinstance(writer,

(FFMpegFileWriter, MencoderFileWriter))):

print("Warning: discarding the 'bbox_inches' argument in "

"'savefig_kwargs' as it is only currently supported "

"with the writers 'ffmpeg_file' and 'mencoder_file' "

"(writer used: "

"'{0}').".format(

writer if isinstance(writer, six.string_types)

else writer.__class__.__name__))

savefig_kwargs.pop('bbox_inches')

# Need to disconnect the first draw callback, since we'll be doing

# draws. Otherwise, we'll end up starting the animation.

if self._first_draw_id is not None:

self._fig.canvas.mpl_disconnect(self._first_draw_id)

reconnect_first_draw = True

else:

reconnect_first_draw = False

if fps is None and hasattr(self, '_interval'):

# Convert interval in ms to frames per second

fps = 1000. / self._interval

# If the writer is None, use the rc param to find the name of the one

# to use

if writer is None:

writer = rcParams['animation.writer']

# Re-use the savefig DPI for ours if none is given

if dpi is None:

dpi = rcParams['savefig.dpi']

if codec is None:

codec = rcParams['animation.codec']

if bitrate is None:

bitrate = rcParams['animation.bitrate']

all_anim = [self]

if extra_anim is not None:

all_anim.extend(anim

for anim

in extra_anim if anim._fig is self._fig)

# If we have the name of a writer, instantiate an instance of the

# registered class.

if is_string_like(writer):

if writer in writers.avail:

writer = writers[writer](fps, codec, bitrate,

extra_args=extra_args,

metadata=metadata)

else:

import warnings

warnings.warn("MovieWriter %s unavailable" % writer)

try:

writer = writers[writers.list()[0]](fps, codec, bitrate,

extra_args=extra_args,

metadata=metadata)

except IndexError:

raise ValueError("Cannot save animation: no writers are "

"available. Please install mencoder or "

"ffmpeg to save animations.")

verbose.report('Animation.save using %s' % type(writer),

level='helpful')

# Create a new sequence of frames for saved data. This is different

# from new_frame_seq() to give the ability to save 'live' generated

# frame information to be saved later.

# TODO: Right now, after closing the figure, saving a movie won't work

# since GUI widgets are gone. Either need to remove extra code to

# allow for this non-existant use case or find a way to make it work.

with writer.saving(self._fig, filename, dpi):

for anim in all_anim:

# Clear the initial frame

if anim._init_func:

anim._init_draw()

for data in zip(*[a.new_saved_frame_seq()

for a in all_anim]):

for anim, d in zip(all_anim, data):

# TODO: Need to see if turning off blit is really necessary

anim._draw_next_frame(d, blit=False)

writer.grab_frame(**savefig_kwargs)

# Reconnect signal for first draw if necessary

if reconnect_first_draw:

self._first_draw_id = self._fig.canvas.mpl_connect('draw_event',

self._start)

def _step(self, *args):

'''

Handler for getting events. By default, gets the next frame in the

sequence and hands the data off to be drawn.

'''

# Returns True to indicate that the event source should continue to

# call _step, until the frame sequence reaches the end of iteration,

# at which point False will be returned.

try:

framedata = next(self.frame_seq)

self._draw_next_frame(framedata, self._blit)

return True

except StopIteration:

return False

def new_frame_seq(self):

'Creates a new sequence of frame information.'

# Default implementation is just an iterator over self._framedata

return iter(self._framedata)

def new_saved_frame_seq(self):

'Creates a new sequence of saved/cached frame information.'

# Default is the same as the regular frame sequence

return self.new_frame_seq()

def _draw_next_frame(self, framedata, blit):

# Breaks down the drawing of the next frame into steps of pre- and

# post- draw, as well as the drawing of the frame itself.

self._pre_draw(framedata, blit)

self._draw_frame(framedata)

self._post_draw(framedata, blit)

def _init_draw(self):

# Initial draw to clear the frame. Also used by the blitting code

# when a clean base is required.

pass

def _pre_draw(self, framedata, blit):

# Perform any cleaning or whatnot before the drawing of the frame.

# This default implementation allows blit to clear the frame.

if blit:

self._blit_clear(self._drawn_artists, self._blit_cache)

def _draw_frame(self, framedata):

# Performs actual drawing of the frame.

raise NotImplementedError('Needs to be implemented by subclasses to'

' actually make an animation.')

def _post_draw(self, framedata, blit):

# After the frame is rendered, this handles the actual flushing of

# the draw, which can be a direct draw_idle() or make use of the

# blitting.

if blit and self._drawn_artists:

self._blit_draw(self._drawn_artists, self._blit_cache)

else:

self._fig.canvas.draw_idle()

# The rest of the code in this class is to facilitate easy blitting

def _blit_draw(self, artists, bg_cache):

# Handles blitted drawing, which renders only the artists given instead

# of the entire figure.

updated_ax = []

for a in artists:

# If we haven't cached the background for this axes object, do

# so now. This might not always be reliable, but it's an attempt

# to automate the process.

if a.axes not in bg_cache:

bg_cache[a.axes] = a.figure.canvas.copy_from_bbox(a.axes.bbox)

a.axes.draw_artist(a)

updated_ax.append(a.axes)

# After rendering all the needed artists, blit each axes individually.

for ax in set(updated_ax):

ax.figure.canvas.blit(ax.bbox)

def _blit_clear(self, artists, bg_cache):

# Get a list of the axes that need clearing from the artists that

# have been drawn. Grab the appropriate saved background from the

# cache and restore.

axes = set(a.axes for a in artists)

for a in axes:

a.figure.canvas.restore_region(bg_cache[a])

def _setup_blit(self):

# Setting up the blit requires: a cache of the background for the

# axes

self._blit_cache = dict()

self._drawn_artists = []

self._resize_id = self._fig.canvas.mpl_connect('resize_event',

self._handle_resize)

self._post_draw(None, self._blit)

def _handle_resize(self, *args):

# On resize, we need to disable the resize event handling so we don't

# get too many events. Also stop the animation events, so that

# we're paused. Reset the cache and re-init. Set up an event handler

# to catch once the draw has actually taken place.

self._fig.canvas.mpl_disconnect(self._resize_id)

self.event_source.stop()

self._blit_cache.clear()

self._init_draw()

self._resize_id = self._fig.canvas.mpl_connect('draw_event',

self._end_redraw)

def _end_redraw(self, evt):

# Now that the redraw has happened, do the post draw flushing and

# blit handling. Then re-enable all of the original events.

self._post_draw(None, self._blit)

self.event_source.start()

self._fig.canvas.mpl_disconnect(self._resize_id)

self._resize_id = self._fig.canvas.mpl_connect('resize_event',

self._handle_resize)

def to_html5_video(self):

r'''Returns animation as an HTML5 video tag.

This saves the animation as an h264 video, encoded in base64

directly into the HTML5 video tag. This respects the rc parameters

for the writer as well as the bitrate. This also makes use of the

``interval`` to control the speed, and uses the ``repeat``

paramter to decide whether to loop.

'''

VIDEO_TAG = r'''<video {size} {options}>

Your browser does not support the video tag.

</video>'''

# Cache the the rendering of the video as HTML

if not hasattr(self, '_base64_video'):

# First write the video to a tempfile. Set delete to False

# so we can re-open to read binary data.

with tempfile.NamedTemporaryFile(suffix='.m4v',

delete=False) as f:

# We create a writer manually so that we can get the

# appropriate size for the tag

Writer = writers[rcParams['animation.writer']]

writer = Writer(codec='h264',

bitrate=rcParams['animation.bitrate'],

fps=1000. / self._interval)

self.save(f.name, writer=writer)

# Now open and base64 encode

with open(f.name, 'rb') as video:

vid64 = base64.encodebytes(video.read())

self._base64_video = vid64.decode('ascii')

self._video_size = 'width="{0}" height="{1}"'.format(

*writer.frame_size)

# Now we can remove

os.remove(f.name)

# Default HTML5 options are to autoplay and to display video controls

options = ['controls', 'autoplay']

# If we're set to repeat, make it loop

if self.repeat:

options.append('loop')

return VIDEO_TAG.format(video=self._base64_video,

size=self._video_size,

options=' '.join(options))

def _repr_html_(self):

r'IPython display hook for rendering.'

fmt = rcParams['animation.html']

if fmt == 'html5':

return self.to_html5_video()

class TimedAnimation(Animation):

'''

:class:`Animation` subclass that supports time-based animation, drawing

a new frame every *interval* milliseconds.

*repeat* controls whether the animation should repeat when the sequence

of frames is completed.

*repeat_delay* optionally adds a delay in milliseconds before repeating

the animation.

'''

def __init__(self, fig, interval=200, repeat_delay=None, repeat=True,

event_source=None, *args, **kwargs):

# Store the timing information

self._interval = interval

self._repeat_delay = repeat_delay

self.repeat = repeat

# If we're not given an event source, create a new timer. This permits

# sharing timers between animation objects for syncing animations.

if event_source is None:

event_source = fig.canvas.new_timer()

event_source.interval = self._interval

Animation.__init__(self, fig, event_source=event_source,

*args, **kwargs)

def _step(self, *args):

'''

Handler for getting events.

'''

# Extends the _step() method for the Animation class. If

# Animation._step signals that it reached the end and we want to

# repeat, we refresh the frame sequence and return True. If

# _repeat_delay is set, change the event_source's interval to our loop

# delay and set the callback to one which will then set the interval

# back.

still_going = Animation._step(self, *args)

if not still_going and self.repeat:

self.frame_seq = self.new_frame_seq()

if self._repeat_delay:

self.event_source.remove_callback(self._step)

self.event_source.add_callback(self._loop_delay)

self.event_source.interval = self._repeat_delay

return True

View remainder of file in raw view

matplotlib/lib/matplotlib/animation.py at patch-1 · flothesof/matplotlib · GitHub

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